Light sensing devices are widely applied to fields of such as inspection equipment for manufacture process, environment monitoring system, color detection management, biomedical measurement and spectrum analysis. A light sensing device has a light sensing unit detecting light from environment and converting the received light into an electronic signal. The electronic signal is processed to obtain required information for a user. However, although the conventional light sensing device is often designed for measurement in various environments, a computing equipment is necessary for analysis and computation of the electronic signals generated by the light sensing device. The additional computing equipment and cable for the computing equipment may cause inconvenience for the user.